;;; smime.el --- S/MIME support library
-;; Copyright (c) 2000 Free Software Foundation, Inc.
+;; Copyright (c) 2000, 2001, 2003 Free Software Foundation, Inc.
;; Author: Simon Josefsson <simon@josefsson.org>
;; Keywords: SMIME X.509 PEM OpenSSL
-;; This file is not a part of GNU Emacs, but the same permissions apply.
+;; This file is part of GNU Emacs.
;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published
;; PKCSx or similar, it's intended to perform common operations
;; done on messages encoded in these formats. The terminology chosen
;; reflect this.
+;;
+;; The home of this file is in Gnus CVS, but also available from
+;; http://josefsson.org/smime.html.
;;; Quick introduction:
;; that decision. One might think that this even influenced were I
;; store my keys, and one would probably be right. :-)
;;
+;; Update: Mathias Herberts sent the patch. However, it uses
+;; environment variables to pass the password to OpenSSL, which is
+;; slightly insecure. Hence a new todo: use a better -passin method.
+;;
+;; Cache password for e.g. 1h
+;;
;; Suggestions and comments are appreciated, mail me at simon@josefsson.org.
-;; <rant>
+;; begin rant
;;
;; I would include pointers to introductory text on concepts used in
;; this library here, but the material I've read are so horrible I
;; Also, I'm not going to mention anything about the wonders of
;; cryptopolitics. Oops, I just did.
;;
-;; </rant>
+;; end rant
;;; Revision history:
-;; version 0 not released
+;; 2000-06-05 initial version, committed to Gnus CVS contrib/
+;; 2000-10-28 retrieve certificates via DNS CERT RRs
+;; 2001-10-14 posted to gnu.emacs.sources
;;; Code:
"S/MIME configuration.")
(defcustom smime-keys nil
- "Map mail addresses to a file containing Certificate (and private key).
-The file is assumed to be in PEM format and not encrypted."
+ "*Map mail addresses to a file containing Certificate (and private key).
+The file is assumed to be in PEM format. You can also associate additional
+certificates to be sent with every message to each address."
:type '(repeat (list (string :tag "Mail address")
- (file :tag "File name")))
+ (file :tag "File name")
+ (repeat :tag "Additional certificate files"
+ (file :tag "File name"))))
:group 'smime)
-(defcustom smime-CA-directory ""
- "Directory containing certificates for CAs you trust.
+(defcustom smime-CA-directory nil
+ "*Directory containing certificates for CAs you trust.
Directory should contain files (in PEM format) named to the X.509
-hash of the certificate."
+hash of the certificate. This can be done using OpenSSL such as:
+
+$ ln -s ca.pem `openssl x509 -noout -hash -in ca.pem`.0
+
+where `ca.pem' is the file containing a PEM encoded X.509 CA
+certificate."
:type '(choice (const :tag "none" nil)
directory)
:group 'smime)
-(defcustom smime-CA-file ""
- "Files containing certificates for CAs you trust.
-File should be in PEM format."
+(defcustom smime-CA-file nil
+ "*Files containing certificates for CAs you trust.
+File should contain certificates in PEM format."
:type '(choice (const :tag "none" nil)
file)
:group 'smime)
(defcustom smime-certificate-directory "~/Mail/certs/"
- "Directory containing other people's certificates.
+ "*Directory containing other people's certificates.
It should contain files named to the X.509 hash of the certificate,
-and the files themself should be in PEM format.
-The S/MIME library provide simple functionality for fetching
-certificates into this directory, so there is no need to populate it
-manually."
+and the files themself should be in PEM format."
+;The S/MIME library provide simple functionality for fetching
+;certificates into this directory, so there is no need to populate it
+;manually.
:type 'directory
:group 'smime)
-(defcustom smime-openssl-program
- (and (condition-case ()
+(defcustom smime-openssl-program
+ (and (condition-case ()
(eq 0 (call-process "openssl" nil nil nil "version"))
(error nil))
"openssl")
- "Name of OpenSSL binary."
+ "*Name of OpenSSL binary."
:type 'string
:group 'smime)
+;; OpenSSL option to select the encryption cipher
+
+(defcustom smime-encrypt-cipher "-des3"
+ "*Cipher algorithm used for encryption."
+ :type '(choice (const :tag "Triple DES" "-des3")
+ (const :tag "DES" "-des")
+ (const :tag "RC2 40 bits" "-rc2-40")
+ (const :tag "RC2 64 bits" "-rc2-64")
+ (const :tag "RC2 128 bits" "-rc2-128"))
+ :group 'smime)
+
+(defcustom smime-crl-check nil
+ "*Check revocation status of signers certificate using CRLs.
+Enabling this will have OpenSSL check the signers certificate
+against a certificate revocation list (CRL).
+
+For this to work the CRL must be up-to-date and since they are
+normally updated quite often (ie. several times a day) you
+probably need some tool to keep them up-to-date. Unfortunately
+Gnus cannot do this for you.
+
+The CRL should either be appended (in PEM format) to your
+`smime-CA-file' or be located in a file (also in PEM format) in
+your `smime-certificate-directory' named to the X.509 hash of the
+certificate with .r0 as file name extension.
+
+At least OpenSSL version 0.9.7 is required for this to work."
+ :type '(choice (const :tag "No check" nil)
+ (const :tag "Check certificate" "-crl_check")
+ (const :tag "Check certificate chain" "-crl_check_all"))
+ :group 'smime)
+
(defcustom smime-dns-server nil
- "DNS server to query certificates from.
+ "*DNS server to query certificates from.
If nil, use system defaults."
:type '(choice (const :tag "System defaults")
string)
- :group 'dig)
+ :group 'smime)
(defvar smime-details-buffer "*OpenSSL output*")
+;; Use mm-util?
+(eval-and-compile
+ (defalias 'smime-make-temp-file
+ (if (fboundp 'make-temp-file)
+ 'make-temp-file
+ (lambda (prefix &optional dir-flag) ;; Simple implementation
+ (expand-file-name
+ (make-temp-name prefix)
+ (if (fboundp 'temp-directory)
+ (temp-directory)
+ temporary-file-directory))))))
+
+;; Password dialog function
+
+(defun smime-ask-passphrase ()
+ "Asks the passphrase to unlock the secret key."
+ (let ((passphrase
+ (read-passwd
+ "Passphrase for secret key (RET for no passphrase): ")))
+ (if (string= passphrase "")
+ nil
+ passphrase)))
+
;; OpenSSL wrappers.
(defun smime-call-openssl-region (b e buf &rest args)
(4 (message "OpenSSL: An error occurred decrypting or verifying the message.") nil)
(t (error "Unknown OpenSSL exitcode") nil)))
+(defun smime-make-certfiles (certfiles)
+ (if certfiles
+ (append (list "-certfile" (expand-file-name (car certfiles)))
+ (smime-make-certfiles (cdr certfiles)))))
+
;; Sign+encrypt region
(defun smime-sign-region (b e keyfile)
"Sign region with certified key in KEYFILE.
If signing fails, the buffer is not modified. Region is assumed to
have proper MIME tags. KEYFILE is expected to contain a PEM encoded
-private key and certificate."
- (let ((buffer (generate-new-buffer (generate-new-buffer-name " *smime*"))))
+private key and certificate as its car, and a list of additional
+certificates to include in its caar. If no additional certificates is
+included, KEYFILE may be the file containing the PEM encoded private
+key and certificate itself."
+ (smime-new-details-buffer)
+ (let ((keyfile (or (car-safe keyfile) keyfile))
+ (certfiles (and (cdr-safe keyfile) (cadr keyfile)))
+ (buffer (generate-new-buffer (generate-new-buffer-name " *smime*")))
+ (passphrase (smime-ask-passphrase))
+ (tmpfile (smime-make-temp-file "smime")))
+ (if passphrase
+ (setenv "GNUS_SMIME_PASSPHRASE" passphrase))
(prog1
- (when (smime-call-openssl-region b e buffer "smime" "-sign"
- "-signer" (expand-file-name keyfile))
+ (when (prog1
+ (apply 'smime-call-openssl-region b e (list buffer tmpfile)
+ "smime" "-sign" "-signer" (expand-file-name keyfile)
+ (append
+ (smime-make-certfiles certfiles)
+ (if passphrase
+ (list "-passin" "env:GNUS_SMIME_PASSPHRASE"))))
+ (if passphrase
+ (setenv "GNUS_SMIME_PASSPHRASE" "" t))
+ (with-current-buffer smime-details-buffer
+ (insert-file-contents tmpfile)
+ (delete-file tmpfile)))
(delete-region b e)
- (insert-buffer buffer)
+ (insert-buffer-substring buffer)
+ (goto-char b)
(when (looking-at "^MIME-Version: 1.0$")
(delete-region (point) (progn (forward-line 1) (point))))
t)
- (with-current-buffer (get-buffer-create smime-details-buffer)
+ (with-current-buffer smime-details-buffer
(goto-char (point-max))
- (insert-buffer buffer))
+ (insert-buffer-substring buffer))
(kill-buffer buffer))))
(defun smime-encrypt-region (b e certfiles)
If encryption fails, the buffer is not modified. Region is assumed to
have proper MIME tags. CERTFILES is a list of filenames, each file
is expected to contain of a PEM encoded certificate."
- (let ((buffer (generate-new-buffer (generate-new-buffer-name " *smime*"))))
+ (smime-new-details-buffer)
+ (let ((buffer (generate-new-buffer (generate-new-buffer-name " *smime*")))
+ (tmpfile (smime-make-temp-file "smime")))
(prog1
- (when (apply 'smime-call-openssl-region b e buffer "smime" "-encrypt"
- (mapcar 'expand-file-name certfiles))
+ (when (prog1
+ (apply 'smime-call-openssl-region b e (list buffer tmpfile)
+ "smime" "-encrypt" smime-encrypt-cipher
+ (mapcar 'expand-file-name certfiles))
+ (with-current-buffer smime-details-buffer
+ (insert-file-contents tmpfile)
+ (delete-file tmpfile)))
(delete-region b e)
- (insert-buffer buffer)
+ (insert-buffer-substring buffer)
+ (goto-char b)
(when (looking-at "^MIME-Version: 1.0$")
(delete-region (point) (progn (forward-line 1) (point))))
t)
- (with-current-buffer (get-buffer-create smime-details-buffer)
+ (with-current-buffer smime-details-buffer
(goto-char (point-max))
- (insert-buffer buffer))
+ (insert-buffer-substring buffer))
(kill-buffer buffer))))
;; Sign+encrypt buffer
(interactive)
(with-current-buffer (or buffer (current-buffer))
(smime-sign-region
- (point-min) (point-max)
- (or keyfile
- (smime-get-key-by-email
- (completing-read "Sign using which signature? " smime-keys nil nil
- (and (listp (car-safe smime-keys))
- (caar smime-keys))))))))
+ (point-min) (point-max)
+ (if keyfile
+ keyfile
+ (smime-get-key-with-certs-by-email
+ (completing-read
+ (concat "Sign using which key? "
+ (if smime-keys (concat "(default " (caar smime-keys) ") ")
+ ""))
+ smime-keys nil nil (car-safe (car-safe smime-keys))))))))
(defun smime-encrypt-buffer (&optional certfiles buffer)
"S/MIME encrypt BUFFER for recipients specified in CERTFILES.
nil."
(interactive)
(with-current-buffer (or buffer (current-buffer))
- (smime-encrypt-region
+ (smime-encrypt-region
(point-min) (point-max)
(or certfiles
(list (read-file-name "Recipient's S/MIME certificate: "
;; Verify+decrypt region
(defun smime-verify-region (b e)
- (let ((buffer (get-buffer-create smime-details-buffer))
- (CAs (cond (smime-CA-file
- (list "-CAfile" (expand-file-name smime-CA-file)))
- (smime-CA-directory
- (list "-CApath" (expand-file-name smime-CA-directory)))
- (t
- (error "No CA configured.")))))
- (with-current-buffer buffer
- (erase-buffer))
- (if (apply 'smime-call-openssl-region b e buffer "smime" "-verify"
- "-out" "/dev/null" CAs)
- (message "S/MIME message verified succesfully.")
- (message "S/MIME message NOT verified successfully.")
+ "Verify S/MIME message in region between B and E.
+Returns non-nil on success.
+Any details (stdout and stderr) are left in the buffer specified by
+`smime-details-buffer'."
+ (smime-new-details-buffer)
+ (let ((CAs (append (if smime-CA-file
+ (list "-CAfile"
+ (expand-file-name smime-CA-file)))
+ (if smime-CA-directory
+ (list "-CApath"
+ (expand-file-name smime-CA-directory))))))
+ (unless CAs
+ (error "No CA configured"))
+ (if smime-crl-check
+ (add-to-list 'CAs smime-crl-check))
+ (if (apply 'smime-call-openssl-region b e (list smime-details-buffer t)
+ "smime" "-verify" "-out" "/dev/null" CAs)
+ t
+ (insert-buffer-substring smime-details-buffer)
nil)))
(defun smime-noverify-region (b e)
- (let ((buffer (get-buffer-create smime-details-buffer)))
- (with-current-buffer buffer
- (erase-buffer))
- (if (apply 'smime-call-openssl-region b e buffer "smime" "-verify"
- "-noverify" "-out" '("/dev/null"))
- (message "S/MIME message verified succesfully.")
- (message "S/MIME message NOT verified successfully.")
- nil)))
+ "Verify integrity of S/MIME message in region between B and E.
+Returns non-nil on success.
+Any details (stdout and stderr) are left in the buffer specified by
+`smime-details-buffer'."
+ (smime-new-details-buffer)
+ (if (apply 'smime-call-openssl-region b e (list smime-details-buffer t)
+ "smime" "-verify" "-noverify" "-out" '("/dev/null"))
+ t
+ (insert-buffer-substring smime-details-buffer)
+ nil))
+
+(eval-when-compile
+ (defvar from))
(defun smime-decrypt-region (b e keyfile)
- (let ((buffer (generate-new-buffer (generate-new-buffer-name "*smime*")))
- CAs)
- (when (apply 'smime-call-openssl-region b e buffer "smime" "-decrypt"
- "-recip" (list keyfile))
-
- )
- (with-current-buffer (get-buffer-create smime-details-buffer)
- (goto-char (point-max))
- (insert-buffer buffer))
- (kill-buffer buffer)))
-
+ "Decrypt S/MIME message in region between B and E with key in KEYFILE.
+On success, replaces region with decrypted data and return non-nil.
+Any details (stderr on success, stdout and stderr on error) are left
+in the buffer specified by `smime-details-buffer'."
+ (smime-new-details-buffer)
+ (let ((buffer (generate-new-buffer (generate-new-buffer-name " *smime*")))
+ CAs (passphrase (smime-ask-passphrase))
+ (tmpfile (smime-make-temp-file "smime")))
+ (if passphrase
+ (setenv "GNUS_SMIME_PASSPHRASE" passphrase))
+ (if (prog1
+ (apply 'smime-call-openssl-region b e
+ (list buffer tmpfile)
+ "smime" "-decrypt" "-recip" (expand-file-name keyfile)
+ (if passphrase
+ (list "-passin" "env:GNUS_SMIME_PASSPHRASE")))
+ (if passphrase
+ (setenv "GNUS_SMIME_PASSPHRASE" "" t))
+ (with-current-buffer smime-details-buffer
+ (insert-file-contents tmpfile)
+ (delete-file tmpfile)))
+ (progn
+ (delete-region b e)
+ (when (boundp 'from)
+ ;; `from' is dynamically bound in mm-dissect.
+ (insert "From: " from "\n"))
+ (insert-buffer-substring buffer)
+ (kill-buffer buffer)
+ t)
+ (with-current-buffer smime-details-buffer
+ (insert-buffer-substring buffer))
+ (kill-buffer buffer)
+ (delete-region b e)
+ (insert-buffer-substring smime-details-buffer)
+ nil)))
+
;; Verify+Decrypt buffer
(defun smime-verify-buffer (&optional buffer)
"Verify integrity of S/MIME message in BUFFER.
-Uses current buffer if BUFFER is nil."
+Uses current buffer if BUFFER is nil. Returns non-nil on success.
+Any details (stdout and stderr) are left in the buffer specified by
+`smime-details-buffer'."
(interactive)
(with-current-buffer (or buffer (current-buffer))
(smime-verify-region (point-min) (point-max))))
(defun smime-noverify-buffer (&optional buffer)
"Verify integrity of S/MIME message in BUFFER.
-Uses current buffer if BUFFER is nil.
-Does NOT verify validity of certificate."
+Does NOT verify validity of certificate (only message integrity).
+Uses current buffer if BUFFER is nil. Returns non-nil on success.
+Any details (stdout and stderr) are left in the buffer specified by
+`smime-details-buffer'."
(interactive)
(with-current-buffer (or buffer (current-buffer))
(smime-noverify-region (point-min) (point-max))))
(defun smime-decrypt-buffer (&optional buffer keyfile)
"Decrypt S/MIME message in BUFFER using KEYFILE.
-Uses current buffer if BUFFER is nil, queries user of KEYFILE is nil."
+Uses current buffer if BUFFER is nil, and query user of KEYFILE if it's nil.
+On success, replaces data in buffer and return non-nil.
+Any details (stderr on success, stdout and stderr on error) are left
+in the buffer specified by `smime-details-buffer'."
(interactive)
(with-current-buffer (or buffer (current-buffer))
- (smime-decrypt-region
+ (smime-decrypt-region
(point-min) (point-max)
(expand-file-name
(or keyfile
(smime-get-key-by-email
- (completing-read "Decrypt with which key? " smime-keys nil nil
- (and (listp (car-safe smime-keys))
- (caar smime-keys)))))))))
+ (completing-read
+ (concat "Decipher using which key? "
+ (if smime-keys (concat "(default " (caar smime-keys) ") ")
+ ""))
+ smime-keys nil nil (car-safe (car-safe smime-keys)))))))))
;; Various operations
+(defun smime-new-details-buffer ()
+ (with-current-buffer (get-buffer-create smime-details-buffer)
+ (erase-buffer)))
+
(defun smime-pkcs7-region (b e)
"Convert S/MIME message between points B and E into a PKCS7 message."
- (let ((buffer (get-buffer-create smime-details-buffer)))
- (with-current-buffer buffer
- (erase-buffer))
- (when (smime-call-openssl-region b e buffer "smime" "-pk7out")
- (delete-region b e)
- (insert-buffer-substring buffer)
- t)))
+ (smime-new-details-buffer)
+ (when (smime-call-openssl-region b e smime-details-buffer "smime" "-pk7out")
+ (delete-region b e)
+ (insert-buffer-substring smime-details-buffer)
+ t))
(defun smime-pkcs7-certificates-region (b e)
"Extract any certificates enclosed in PKCS7 message between points B and E."
- (let ((buffer (get-buffer-create smime-details-buffer)))
- (with-current-buffer buffer
- (erase-buffer))
- (when (smime-call-openssl-region b e buffer "pkcs7" "-print_certs" "-text")
- (delete-region b e)
- (insert-buffer-substring buffer)
- t)))
+ (smime-new-details-buffer)
+ (when (smime-call-openssl-region
+ b e smime-details-buffer "pkcs7" "-print_certs" "-text")
+ (delete-region b e)
+ (insert-buffer-substring smime-details-buffer)
+ t))
(defun smime-pkcs7-email-region (b e)
"Get email addresses contained in certificate between points B and E.
A string or a list of strings is returned."
- (let ((buffer (get-buffer-create smime-details-buffer)))
- (with-current-buffer buffer
- (erase-buffer))
- (when (smime-call-openssl-region b e buffer "x509" "-email" "-noout")
- (delete-region b e)
- (insert-buffer-substring buffer)
- t)))
-
-(defalias 'smime-point-at-eol
- (if (fboundp 'point-at-eol)
- 'point-at-eol
- 'line-end-position))
+ (smime-new-details-buffer)
+ (when (smime-call-openssl-region
+ b e smime-details-buffer "x509" "-email" "-noout")
+ (delete-region b e)
+ (insert-buffer-substring smime-details-buffer)
+ t))
+
+;; Utility functions
+
+(defun smime-get-certfiles (keyfile keys)
+ (if keys
+ (let ((curkey (car keys))
+ (otherkeys (cdr keys)))
+ (if (string= keyfile (cadr curkey))
+ (caddr curkey)
+ (smime-get-certfiles keyfile otherkeys)))))
(defun smime-buffer-as-string-region (b e)
"Return each line in region between B and E as a list of strings."
(goto-char b)
(let (res)
(while (< (point) e)
- (let ((str (buffer-substring (point) (smime-point-at-eol))))
+ (let ((str (buffer-substring (point) (point-at-eol))))
(unless (string= "" str)
(push str res)))
(forward-line))
(erase-buffer)
(insert "\nYour keys:\n")
(dolist (key smime-keys)
- (insert
+ (insert
(format "\t\t%s: %s\n" (car key) (cadr key))))
(insert "\nTrusted Certificate Authoritys:\n")
(insert "\nKnown Certificates:\n"))))
(defun smime-get-key-by-email (email)
(cadr (assoc email smime-keys)))
+(defun smime-get-key-with-certs-by-email (email)
+ (cdr (assoc email smime-keys)))
+
(provide 'smime)
+;;; arch-tag: e3f9b938-5085-4510-8a11-6625269c9a9e
;;; smime.el ends here
projects / gnus / blobdiff